Segui questo link per vedere altri tipi di pubblicazioni sul tema: Phosphine – Synthesis.
Tesi sul tema "Phosphine – Synthesis"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Phosphine – Synthesis".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Prabagar, Jasotha. "Synthesis of bulky phosphine ligands." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437012.
Testo completo
2
Dai, Xuedong 1970. "Synthesis of novel phosphine ligands." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36078.
Testo completo
3
Tyzack, Charles Richard. "Stereocontrolled synthesis using phosphine oxides." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620349.
Testo completo
4
Hutton, Gordon Eric. "Stereocontrol with phosphine oxides." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/273009.
Testo completo
5
Armstrong, S. K. "Homoallylic amine synthesis using phosphine oxides." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596156.
Testo completoAbstract (sommario):
This thesis will describe the development of a new route to homoallylic amines 9, in four steps from alcohols 1, or acetals 2, which may themselves have to be synthesised. The synthesis is stereoselective, and generates <i>E</i>-9 and <i>Z</i>-9 quite separately, thereby avoiding the sometimes difficult separation of these isomers. Alkenes 3, readily available from alcohols 1 or acetals 2, undergo regio- and stereo-selective 1,3-dipolar cycloadditions with nitrile oxides 4 or nitrones 6. The resulting heterocycles 5 and 7 are reductively cleaved to give β-hydroxy-δ-aminoalkyldiphenylphosphine oxides 8. These alcohols undergo Horner-Emmons-type elimination of sodium diphenylphosphinite to give homallylic amines 9, stereospecifically. Isoxazolines 5, resulting from nitrile oxide cycloadditions, undergo stereoselective reduction, and give rise to primary amines 9, R<SUP>3 =</SUP> H. Isoxazolines 7, resulting from nitrone cycloadditions, give rise to secondary amines 9, R<SUP>3 =</SUP> alkyl or aryl. When the alkoxy substituted alkenes 3, R<SUP>1 =</SUP> OR are used, protected enol ethers 9, R<SUP>1 =</SUP> OR, R<SUP>3 =</SUP> Ac are the final products. The vital cycloaddition and reduction steps are both high yielding, although the elimination is often less so.
6
Armstrong, Susan Katherine. "Phosphine oxides in homoallyic amine synthesis." Thesis, University of Cambridge, 1991. https://www.repository.cam.ac.uk/handle/1810/272612.
Testo completo
7
Swor, Charles D. (Charles David) 1982. "Synthesis, coordination chemistry, and reactivity of functionalized phosphines: Toward water-soluble macrocyclic phosphine complexes." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11264.
Testo completoAbstract (sommario):
xx, 290 p. : ill. (some col.)<br>Macrocyclic phosphine compounds have long been sought as ligands for transition metal complexes because of their strong binding properties. Despite considerable effort in this field, no general methods for synthesizing phosphine macrocycles or their complexes have been developed. This dissertation describes attempts to synthesize an iron complex with a water-soluble macrocyclic tetraphosphine ligand for use in separating nitrogen from natural gas. Chapter I reviews previous syntheses of macrocyclic phosphine ligands and their complexes, focusing on ligand synthesis, coordination chemistry, and demetallation of the complexes.
Chapter II reports on the synthesis of water-soluble secondary bidentate phosphine ligands, their coordination chemistry with iron(II), and attempts to use these complexes as templates for forming a macrocyclic iron-phosphine complex by reactions with carbon electrophiles.
Over the course of treating these iron complexes with various carbon electrophiles, an interesting reaction between bromomaleic anhydride and proton sponge was discovered. Chapter III explores the product, 4-maleicanhydrido-1,8-bis-(dimethylamino)naphthalene (MAPS). Due to its conjugated donor-acceptor network, which is disrupted upon protonation, MAPS acts as a colorimetric version of a proton sponge. The attachment of MAPS to amine-functionalized solid supports, forming solid-supported proton sponge reagents, is also described.
Chapter IV discusses the synthesis of an iron(II) complex of the water-soluble phosphine 1,2-bis(di(hydroxymethyl)phosphino)ethane (DHMPE). Although unbound hydroxymethylphosphines commonly react with NH-functional amines via the phosphorus Mannich reaction, this and other complexes of DHMPE do not undergo this reaction. Further investigation with hydroxymethylphosphine-boranes suggests that the currently-accepted mechanism of the phosphorus Mannich reaction is incorrect, and an alternate mechanism is proposed.
Chapter V discusses the synthesis and functionalization of copper(I) complexes of water-soluble phosphines. Unlike the complexes described in Chapter I, these complexes readily react with α,ω-dihalides or di(acyl chloride)s, forming complexes whose mass spectra correspond to those with macrocyclic phosphine ligands. Unlike most macrocyclic tetraphosphine complexes, these complexes can be demetallated by treatment with sulfide. Finally, a new synthesis of water-soluble macrocycles, based on lessons learned during the course of these investigations, is proposed.
This dissertation includes previously published and unpublished co-authored material.<br>Committee in charge: Dr. Michael M. Haley, Chairperson;
Dr. David R. Tyler, Advisor;
Dr. Darren W. Johnson, Member;
Dr. Shih-Yuan Liu, Member;
Dr. Mark H. Reed, Outside Member
8
Lin, Qinghong Chemistry Faculty of Science UNSW. "Chiral phosphine synthesis by the application of directed metallation." Awarded by:University of New South Wales. School of Chemistry, 1999. http://handle.unsw.edu.au/1959.4/19347.
Testo completoAbstract (sommario):
The ortho metallation of some aromatic ring systems has been investigated in regard to the influence of several types of phosphorus-centred directing groups upon the reactivity, regioselectivity, and utility in later synthetic elaboration. The metallation step allows derivatisation in several useful ways, offering several routes to the synthesis of novel chiral ditertiary phosphines. Thus, an ortho lithiation of N,N,N',N'-tetramethyl-P-phenylphosphonic diamide (10) led to the interesting primary phosphine, 2-(diphenylphosphino)phenylphosphine (14), after elaboration of the phosphonic diamide directing group. This primary phosphine undergoes an unprecedented facile phenyl group exchange process between its two phosphorus atoms, upon di-lithiation of the primary phosphorus centre. The primary phosphorus centre of (14) has been elaborated in several ways to yield new ditertiary phosphines. The alkylation of this centre in the copper(I) chelate complex has been investigated in several directions. In another direction, (14) has been chemically elaborated to give a new hybrid chiral ditertiary phosphine ligand, "SemiPHOS", containing both a chiral phospholane ring and an adjacent diphenylphosphino group. SemiPHOS has been obtained in optically pure forms by a stereoselective synthesis and, independently, by a resolution procedure on its racemate. The molecular design of SemiPHOS was devised such that, when chelated to a metal atom, a subtle steric interaction appears to allow the chirality of the phospholane ring to influence the neighbouring diphenylphosphino group to adopt a complementary chiral conformation. This idea was tested and evaluated by applying SemiPHOS in catalytic asymmetric hydrogenations of (Z)-a-(Nacylamino) acrylate substrates to produce the R-amino acid precursors. Aryl species lithiated ortho to phosphorus-centred directing groups were coupled oxidatively by a convenient in situ method, to yield biaryl species that could then be elaborated to give biaryl ditertiary phosphine ligands. This method was used to make several atropisomeric chiral ditertiary phosphines.
9
Phelps, Jennifer. "Synthesis of homoleptic PT(0) acceptor phosphine complexes." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594481221&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Testo completo
10
Driver, Mark Peter. "Synthesis and coordination chemistry of multidentate phosphine ligands." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/97142/.
Testo completoAbstract (sommario):
The work presented herein is concerned with the design, synthesis and characterisation of novel phosphorus containing ligands and the metal complexes thereof. Chapter 1 will provide an introduction to the field and present an overview of recent developments in the literature. Chapter 2 deals with the development of a synthetic route towards triphosphine macrocycles. The synthesis of bis(2-(phosphino)ethyl)phosphines is presented and their coordination chemistry with first row transition metals (Cr, Fe, Ni, Cu) is described. The ability of these complexes to act as templates in the formation of macrocyclic ligands is assessed. Chapter 3 explores the synthesis of novel chiral multidentate phosphine ligands derived from glycidyl phosphine synthons. The reaction of diphenylglycidyl phosphine with P, N and S based nucleophiles results in the rapid construction of chiral heterodonor ligand frameworks. Preliminary studies of the reactivity of these ligands with metal centres will be presented. Chapter 4 investigates the synthesis of chiral-at-aluminium complexes based upon a novel γ-amino-β-hydroxyphosphine oxide ligand. Two discreet aluminium alkyl complexes were identified and the interconversion of these species was studied by spectroscopic and computational means. Chapter 5 concerns the coordination chemistry of bicyclic multidentate ER-NHCs with Pd(0), Pt(0) and Au(I) metal centres. The M(0) complexes display an unexpected proclivity towards the κ1-C coordination mode. This further informs the discussion of the factors controlling the variable coordination chemistry of such ligands in the design of novel catalytic systems.
11
Dai, Xuedong 1970. "Synthesis and applications of atropisomeric quinazolinone phosphine ligands." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47887.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1998.<br>Includes bibliographical references.<br>Several novel atropisomeric phosphine ligands have been synthesized and evaluated. The syntheses of 2-methyl-3-[2'-(diphenylphosphino)phenyl]-4(3H)- quinazolinone (la) and its methyl-substituted analogs lb and ic were achieved in good yield by coupling N-acetylanthranilic acid with the corresponding phosphinoanilines 4a-c. A practical resolution of ligands la-c was accomplished using the benzenesulfonylhydrazone derivative (10) of (1S)-(+)-camphorsulfonic acid as a novel resolving agent. Several catalytic reactions including palladium-catalyzed asymmetric allylic alkylation, phosphine-catalyzed [3+2] cycloaddition of N-tosylimines with 2,3- butadienoate, and asymmetric intramolecular Heck reaction were performed. The 2-methyl group of this ligand series could be activated into the olefin form in the presence of Rh(nbd)2C104. The rhodium complex was found to be able to catalyze conjugate addition of the Grignard reagent (n-BuMgBr) to enones. The synthesis of 3-[4',6'-dimethyl-2'-(diphenylphosphino)phenyl]-4(3H)- quinazolinone (id) was achieved by coupling 4H-3,1-benzoxazin-4-one (71) with 4,6- dimethyl-2-diphenylphosphinoaniline (4c). Ligand ld could be directly lithiated by lithium diisopropylamide (LDA). The hetero-substituted analogs le-g were synthesized in good yield by quenching the lithium anion of ligand id with electrophiles. Resolutions of ligands id and le were achieved using (-)-di-p-chloro-bis[(S)-dimethyl-(1- naphthylethyl)aminato-C 2 , N]dipalladium(II) (78) and (-)-di-ji-chloro-bis[(S)-dimethyl-(1- phenylethyl)aminato-C 2 , N]dipalladium(II) (7), respectively.<br>by Xuedong Dai.<br>Ph.D.
12
Sun, Lijie. "Synthesis of atropisomeric 1-Naphthamide-Derived phosphines and application for asymmetric heck and Suzuki-Miyaura reactions /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202009%20SUN.
Testo completo
13
He, Song Helen, and 何松. "Synthesis and applications of polystyrene-supported phosphine and arsine reagents." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38646122.
Testo completo
14
Crabill, Todd W. "The synthesis and study of a crown ether functionalized with both phosphine and phenol groups." Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1327790.
Testo completoAbstract (sommario):
This study has resulted in a crown ether functionalized with both phosphine and phenol groups, 5-diphenylphosphino-1,3-xylyl-18-crown-5. The target molecule was obtained from a six step synthesis. 4-Bromophenol was treated in sequence with formaldehyde, dimethylsulfate, and phosphorus tribromide producing 4-bromo-2,6-bis(bromomethyl)anisole. The main intermediate, 5-diphenylphosphino-1,3-xylyl-18-crown-5, was obtained by treating 4-bromo-2,6-bis(bromomethyl)anisole in sequence with tetraethylene glycol, lithium iodide, and methyldiphenyl phosphonite. The lithium iodide cleaved the anisole-to-methyl group bond, and the methyldiphenyl phosphonite provided the phosphine group for the crown ether following a lithium bromine exchange reaction. The 31P NMR of the phosphine crown ether showed a single signal at 6 -5.9, showing consistency of a single product. The IH NMR of the phosphine crown ether in deuterated chloroform showed signals at 6 3.55-3.7 (crown CH2), 6 4.6 (benzylic CH2), 6 7.1 (d, J = 7.o Hz, crown aromatic CH2), and 6 7.2-7.4 (noncrown aromatic CH2).<br>Department of Chemistry
15
Larkin, Scott A. "Synthesis and Supermolecular Chemistry of Biphenylthioatogold(I)Phosphine Complexes." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/LarkinSA2007.pdf.
Testo completo
16
Bowen, C. J. "Self-Assembly and Solvent Free Synthesis with Phosphine Ligands." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.527662.
Testo completo
17
Farrer, M. J. "Synthesis of electrospray-active phosphine ligands and their complexes." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598946.
Testo completoAbstract (sommario):
This thesis is concerned with the synthesis and characterisation of electrospray-active phosphine ligands and their complexes, focusing on derivatives of proton sponges and bisphosphine monoxides (BPMOs). Phosphines containing Proton Sponge<sup>®</sup> (1,8-<i>bis</i>(dimethylamino)naphthalene, 1a) have been synthesised via sequential bromination, lithiation and phosphination to give [{1,8-<i>bis</i>(dimethylamino)naphthalen-4-yl}diphenylphosphine] (12b), [{1,8-bis(dimethylamino)naphthalen-2-yl}diphenylphosphine] (12a) and [<i>bis</i>{1,8-<i>bis</i>(dimethylamino)naphthalen-2-yl}phenylphosphine] (13a). Complexes of 12a were shown to provide strong ESI-MS signals through the exclusive coordination of H<sup>+</sup>; [Mn(MeCp)(CO)<sub>2</sub>(12a)] (14) and [W(CO)<sub>5</sub>(12a)] (15) and iron carbonyl complexes of the form [Fe(CO)<sub>4</sub>(P)] (P = PPh<sub>3</sub>, P(<i>p</i>-C<sub>6</sub>H<sub>4</sub>OMe)<sub>3</sub>, 12a) (16a-c) have been synthesised and characterised. The relative abilities of the phosphines ligands to act as electrospray handles within these complexes is discussed. The synthesis of a [Ru(η<sup>6</sup>-<i>p</i>-cymene)C1<sub>x</sub>(12a)] species from [Ru(η<sup>6</sup>-<i>p</i>-cymene)Cl<sub>2</sub>]<sub>2</sub> monitored and was shown to proceed through a long-lived detectable intermediate. 12a has been substituted onto PdCl<sub>2</sub>(COD) and PtCl<sub>2</sub>(COD) to form the [MC1<sub>2</sub>(12a)<sub>2</sub>] species. The interactions of 12a and 12a.HX with the Pd(0) complex [Pd(dba)<sub>2</sub>], both in the absence and presence of 4-bromonitrobenzene, have been analysed by ESI-MS. The behaviour of both 12a and 12b has been investigated in a Suzuki (i.e. palladium-mediated) coupling reaction. The characteristics of BPMOs and the potential for these species to act as electrospray handles is described. Via <i>ortho</i>-lithiation of triphenylphosphine oxide with phenylithium and the reactions of the lithiated intermediate with electrophiles (TMSC1, D<sub>2</sub>O, MeI, PR<sub>2</sub>Cl<sub> </sub>and PPhCl<sub>2</sub>) a number of <i>ortho-</i>substituted products have been obtained. For reaction with PR<sub>2</sub>Cl (where R = Ph, <i>i</i>Pr, Cy, Et) a range of BPMOs of the form Ph<sub>2</sub>P(O)(<i>o</i>-C<sub>6</sub>H<sub>4</sub>)PR<sub>2</sub> have been synthesised. Reduction of 26a to give the bisphosphine product <i>o</i>-C<sub>6</sub>H<sub>4</sub>(PPh<sub>2</sub>)<sub>2</sub> (dppbz) is also discussed. The reaction of [MC1<sub>2</sub>COD] (M = Pt, Pd) with 26a formed the following complexes as mixtures; <i>cis</i>[PtCl<sub>2</sub>(26a)<sub>2</sub>] (31), [PtCl<sub>2</sub>(26a)] (32), [PdCl<sub>2</sub>(26a)] (33), [PdCl<sub>2</sub>(26a)<sub>2</sub>] (34) and [Pd<sub>2</sub>Cl<sub>4</sub>(26a)<sub>2</sub>] (35). These were characterised by ESI-MS, <sup>31</sup>P and <sup>195</sup>Pt NMR. An X-ray crystallographic structure of 32 was also determined. Synthesis of [Fe(CO)<sub>4</sub>(26a)] (36) is described. The relevance of these results with a view to observance of metal complexes by ESI-MS is then discussed.
18
Roberts, Huw John. "Synthesis of novel aryl and alkyl phosphine-imidazolium salts." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54669/.
Testo completoAbstract (sommario):
Several chelating phosphine-imidazolium salts have been synthesised and their activity tested in the hydrosilylation of styrene with triethylsilane and the Heck coupling of aryl bromides and chlorides with butyl acrylates. A number of synthetic routes have been established to synthesise aryl substituted phosphine-imidazolium salts. New synthetic routes have been established to synthesise borane-protected alkyl substituted phosphine-imidazolium salts. These methodologies have increased the scope to synthesise new alkyl substituted phosphine-imidazolium salts. Several group 9 and 10 complexes of these new aryl substituted phosphine-NHC ligands have been synthesised and characterised. The NHC's were generated in situ and reacted with suitable metal precursors. Platinum (0) complexes of these ligands were tested in the hydrosilylation of styrene with triethylsilane. Pd(0) complexes of these ligands were tested in the Heck coupling of aryl bromides and chlorides with butyl acrylate.
19
Varrone, Maurizio. "Synthesis and applications of multifunctional N-pyrrolyl phosphine ligands." Thesis, University of Bath, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269821.
Testo completo
20
Kendall, Alexander. "Synthesis, Study, and Catalysis of New Dimethyl-Phosphine Ligands." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20408.
Testo completoAbstract (sommario):
Two new general synthetic routes to phosphines were developed. The first method described directly converts phosphonates to phosphine oxides using organometallic nucleophiles. This reaction proceeds through a five-coordinate phosphorus intermediate. The second synthetic method uses a deprotonated secondary phosphine oxide for nucleophilic addition to an alkyl halide to form a tertiary phosphine oxide. This reaction proceeds through a standard SN2 mechanism, however in extreme cases a competitive electron transfer reaction was observed.
These syntheses were used to make a new dimethyl phosphine (MeJPhos). This phosphine was used as a ligand for metal complexes and compared against a series of structurally related (JohnPhos) phosphines. MeJPhos was found to be the strongest electron donor in the series MeJPhos, EtJPhos, iPrJPhos, CyJPhos, and tBuJPhos.
These ligands were then used to study structural effects of ligands on Buchwald-Hartwig cross-coupling catalysis. It was found that only tBuJPhos performed catalytically. This observation is likely due to the smaller steric profile of the other JohnPhos ligands. Specifically, it is the inability to perform the reductive elimination step of the catalytic cycle that prevents turnover.
Ozonolysis was used to oxidize alkenes to aldehydes directly. Typically with ozonolysis, a secondary ozonide is formed as the product that must be chemically reacted in a subsequent step. By trapping out the immediate chemical precursor to the secondary ozonide with water, the formation of secondary ozonides was avoided. This method produced aldehydes directly from aryl alkenes in good to excellent yields.
This dissertation includes previously published and unpublished co-authored material.
21
Brenchley, Guy. "A new class of phosphine ligand for asymmetric synthesis." Thesis, University of Bath, 1995. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760671.
Testo completo
22
Keefer, Chad D. "The synthesis and study of a phosphine functionalized crown ether." Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1318448.
Testo completoAbstract (sommario):
This study has resulted in a phosphine funetionalized crown ether. synrdiQ-methoxy-5-diphenylphosphino-1.3-cplyl l-24-crown-6, obtained tkmt a live step synthesis. 4-13romophenol was treated in turn with formaldehyde. di methyl sulfate, and phosphorous trihromide. producing 4-bromo-2.6-his(bromomethyl )anisole. The key intermediate. spm-di(2-methoz}-5-bromo-I.3-z( I).l )-24-crown-6. was obtained from treating 4-hromo-3.6-bis(bromomethyl )anisole with diethylenc glycol and potassium thutoyide. The potassium ion apparently provided a template to assist the formation of the product. SLm-di(2-methosp-5-diphenylphosphino- I.3-x lyl )-24-crown-6 was obtained from treating sm-di(2-methos5-5-hromo-I.3-x'kI -24-crown-6 in sequence with n-BuLi and methyldiphern I phosphinite. The nP NMR of the phosphine crown ether showed a single signal at 6 -5.35 ppm. consistent with the formation of a single product.The'1I NMR of the phosphine crown ether in chloroform-d showed signals at6354-3.56 (crown CIF). 3.61 I OCI I;I. 4.44 (benzylic Cl I.6 and 7.25-7.29 (aromatic Ii) ppm.The integrated areas were consistent with the formula. The `C NNIR of the phosphine crown ether in chloroform-d displaced signals at 6 63.1, 68.5. 70.0. 70.1. 128.5 and 128.6 (d). 128.7. 131.8 and 131.9 (d), 132.0. 133.6 and 133.7 (d). 136.1 and 136.4 (d). 137.4 and 137.5 (dl, and 158.4 ppm. The "C signals were consistent with the formula and structure. The br)minated crown ether was characterized with 'I I and ''C NMR. as well as X-ray crystallography and elemental analysis.<br>Department of Chemistry
23
McDaniel, Alicia L. "Synthesis and Characterization of Bis-Phosphine Complexes with Transition Metals." TopSCHOLAR®, 2009. http://digitalcommons.wku.edu/theses/110.
Testo completoAbstract (sommario):
Extractants and extraction methodologies play a vital role in many industrial processes, from the concentration of precious metals from ores to the separation of longlived nuclei from radioactive waste as well as the removal of heavy metals from soils and water for remediation. The vast majority of extractants rely on the use of nitrogen, oxygen, sulfur or selenium as Lewis base donor atoms to form coordination complexes with the metal ions of interest. These extractants often make use of the chelate effect and/or the macrocyclic effect in order to form stable complexes. Some of the best known types of chelate extractants include polyaminopolycarboxylic acids (N and O donors), polyamines (N donors), dithiocarbamate (S donors) and aminopolythias (N and S donors). The most extensively investigated types of macrocycles include crown ethers (O donors), thia crowns (S donors), aza crowns (N donors) and thiacrown ethers (S and O donors).
A conspicuous omission from the list of donor atoms is phosphorus. It is noted that phosphorus has been employed as a backbone atom in the development of extractants, primarily in phosphonates, phosphates and phosphine oxides. The omission of phosphorus is interesting from two points. First, many of the precious and heavy metal ions of interest (Pd2+, Ag+, Pt2+, Pb2+, Cd2+and Hg2+) can be classified as soft Lewis acids, according to Pearson’s HSAB theory. The relative softness of phosphorus as a Lewis base as compared to oxygen and nitrogen indicates that phosphorus would be a very good donor atom toward these soft metal cations. Secondly, chelating agents containing phosphorus donors form stable complexes with transition metal cations in a variety of oxidation states due to their versatile bonding capability. The !-donor characteristics of the phosphine donor coupled with the ability to " accept from filled or partially filled d orbitals of the metal cations result in strong phosphine-metal bonds.
24
He, Song Helen. "Synthesis and applications of polystyrene-supported phosphine and arsine reagents." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38646122.
Testo completo
25
Yenikaya, Cengiz. "Synthesis and structural studies of phosphine oxides and their cocrystals." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388967.
Testo completo
26
Henry, Christopher Edwin. "Phosphine-catalysis of allenoates mechanism, heterocycle synthesis, and asymmetric catalysis /." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1779690221&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Testo completo
27
Freiberg, Evan 1974. "Synthesis, characterization, and reactivity of low valent technetium phosphine complexes." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8252.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2001.<br>Vita.<br>Includes bibliographical references.<br>Chapter 1. The chemistry of the metal-metal multiply bonded Tc2(II,II) core has been investigated with bis(diphenylphosphino)methane (dppm). The parent complex, Tc2Cl4(dppm)2, has been prepared from the reaction of Tc2C14(PEt3)4 with dppm. The reactivity of Tc2Cl4(dppm)2 with tert-butyl isocyanide has been studied and a neutral 1:1 adduct, Tc2Cl4(dppm)2CNBut, a cationic 1:2 adduct, [Tc2Cl3(dppm)4(CNBut)2](PF6), and a [mu]-iminyl complex, [Tc2Cl3(dppm)2(CNBut)2CNHBul(PF6), have been prepared. The parent compound and its reaction products have been characterized via a combination of spectroscopic techniques and single crystal X-ray crystallography. The metal-metal bonded ditechnetium bis(dppm) motif is retained in the reaction products. Chapter 2. The reduction of ammonium pertechnetate with bis(diphenylphosphino)methane (dppm), and with diphenyl-2-pyridyl phosphine (Ph2Ppy), has been investigated. The neutral Tc(II) complex, TcCl2(dppm)2, has been isolated from the reaction of (NH4)[TcO4] with excess dppm in refluxing EtOH/HCl. Chemical oxidation with ferricinium hexafluorophosphate results in formation of the cationic Tc(III) analogue, [TcCl2(dppm)2](PF6). The dppm ligands adopt the chelating bonding mode in both complexes, resulting in strained four member metallocycles. With excess PhPpy, the reduction of (NH4)[TcO4] in refluxing EtOH/HCl yields a complex with one chelating Ph2Ppy ligand and one unidentate Ph2Ppy ligand, TcCl3(Ph2Ppy-P,N)(Ph2Ppy-P).<br>(cont.) The cationic Tc(III) complexes, [TcCl2(dppmO-P, O)2](PF6) and [TcCl2(Ph2P(O)py-N, O)2](PF6) (dppmO = bis(diphenylphosphino)methane monoxide, Ph2P(O)py = diphenyl-2-pyridyl phosphine monoxide), have been isolated as by-products from the reactions of (NH4)[TcO4] with the corresponding phosphine. The products have been characterized in the solid state and in solution via a combination of single crystal X-ray crystallography and spectroscopic techniques. The solution state spectroscopic results are consistent with the retention of the bonding modes revealed in the crystal structures. Chapter 3. A new route to low valent technetium complexes containing multiple acetonitrile ligands has been developed. The reduction of TcCl4(PPh3)2 with zinc metal dust in acetonitrile results in the formation of [Tc(CH3CN)4(PPh3)2][Zn2Cl6]1/2. The hexafluorophosphate salt of the analogous Tc(II) cation can be prepared via chemical oxidation of the Tc(I) species, and the Tc(I) cation can be regenerated via chemical reduction. The compounds have been characterized in the solid state via single crystal X-ray crystallography, and in solution via a combination of spectroscopic techniques and cyclic voltammetry. The structural parameters found in the two complexes are similar to each other; however, the difference in oxidation state is reflected, as expected, in the spectroscopic results. The electrochemical data, obtained from cyclic voltammograms of [Tc(CH3CN)4(PPh3)2](PF6)n (n = 1,2), mirror the synthetic results in that both compounds possess a reversible redox couple at -0.55 V versus ferrocene, which has been assigned to the Tc(II)/Tc(I) couple.<br>by Evan Freiberg.<br>Ph.D.
28
Yamamoto, Takeshi. "Polyquinoxaline-Based Helically Chiral Phosphine Ligands for Catalytic Asymmetric Synthesis." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/131894.
Testo completo
29
Baniasadi, Hamid R. "The synthesis and study of new phosphines functionalized with crown ethers." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1398707.
Testo completoAbstract (sommario):
The goal of this research was to synthesize and study new phosphine crown ethers. The first target molecule was 5-phenylphoshinobis(2-hydroxy,1,3-xylyl-18-crown-5). We tried to synthesize this target molecule in six steps. 5-Bromophenol was reacted with formaldehyde, dimethylsulfate, phosphorus tribromide and tetraethylene glycol in the presence of sodium hydride producing the main intermediate molecule, 5-bromo-2-methoxy-1,3-xylyl-l8-crown-5. This molecule was reacted with n-butyllithium and dimethyl phenylphosphinite at the low temperature . NMR evidence indicated that was not obtained.The second target molecule, the oxide of 5-phenylphosphinobis(2-hydroxy-1,3-xylylcrown-5) was synthesized in nine steps. The main intermediate, 5-bromo-2-methoxy-1,3-xylyl-18-crown-5 was reacted with n-butyllithium and dimethyl phenylphosphinite to form the phosphine. This phosphine was oxidized with hydrogen peroxide. The OCH3 bond of this crown ether was cleaved by using LiI in boiling anhydrous pyridine. NMR data indicated the product was formed.<br>Department of Chemistry
30
Carey, Joseph Vincent. "New bisphosphine ligands for asymmetric catalysis." Thesis, University of Oxford, 1991. http://ora.ox.ac.uk/objects/uuid:c1261e8d-baf4-476a-8954-f943588e1579.
Testo completoAbstract (sommario):
The success of homogeneous asymmetric catalysis has been attributed to the structure and stereochemistry of the coordinated ligand(s). The most effective ligands are C<sub>2</sub>-symmetrical bisphosphines containing either a rigid chiral backbone linking two PPh<sub>2</sub> units or a bisphosphine, DIPAMP containing two chiral phosphine units linked by an achiral backbone. The synthesis of P-chiral ligands of this type has been severely hindered by the lack of a general synthetic route allowing the incorporation of phosphorus chirality without the need for separation of diastereomeric precursors or resolution of intermediate enantiomers. The objective of this work was to develop a general synthetic route to homochiral bulky arylphosphines with substantial flexibility in the groups at phosphorus and extend the approach to new P-chiral bisphosphines. In one approach, diastereomerically pure (2R, 4S, 5R)-2,5-diphenyl-3,4-dimethyl-1,3,2-oxazaphospholidine was prepared directly from PhPCl<sub>2</sub> using l-ephedrine as a chiral auxiliary. Stereospecific oxidation using Bu<sup>t</sup>OOH gave the corresponding P-oxide which was shown to have R-stereochemistry at phosphorus by single-crystal X-ray diffraction studies. The compound reacted regiospecifically with ortho-anisylmagnesium bromide to afford the product formed by P-O bond cleavage with >96% d.e. and with retention of configuration at phosphorus as demonstrated by single-crystal X-ray diffraction studies. The l-ephedrine residue was replaced by O-methyl under acid-catalysis with inversion of configuration and with >95% e.e., the reaction was monitored by <sup>1</sup>H n.m.r. spectroscopy which gave t<sub>1/2</sub> of ca. 30 min. Attempts to incorporate para-fluorophenol using similar conditions led to the isolation of the pyrophosphinate in low yield. The OMe residue in the methyl (ortho-anisyl)phenylphosphinate was readily displaced by aliphatic Grignard reagents giving the corresponding phosphine oxides with inversion of configuration and with >95% e.e. Displacement of methoxy using aryl magnesium bromides showed similar enantioselectivity but in lower chemical yield, however the corresponding arylmagnesium chlorides were more efficient. In a second approach, diastereomerically pure (2R, 4S, 5R)-2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine was prepared from PCl<sub>3</sub> and l-ephedrine. The compound underwent diastereoselective P-C1 cleavage with aryl Grignard and aryllithium reagents with net retention of configuration at phosphorus and with 90% d.e. Oxidation of the ortho-anisyl derivative afforded (2R, 4S, 5R)-2-(ortho-anisyl)-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine-2-oxide which was subsequently reacted with a range of bulky aryl Grignard reagents to afford the corresponding biarylphosphinamides with retention of configuration at phosphorus. Subsequent acid-catalysed methanolysis and displacement of the methoxy residue with PhMgCl afforded a range of bulky arylphosphine oxides with defined configuration at phosphorus with >95% e.e. as determined by <sup>1</sup>H n.m.r. methods. (S)-ortho-anisyl (meta-anisyl)phenylphosphine oxide underwent regiospecific ortho-lithiation on the meta-anisyl ring which on quenching with D<sub>2</sub>O afforded the corresponding 2-deuteride in 80% yield. The 2-iodo analogue was also prepared although in low chemical purity and is a key precursor to new axially dissymmetric bisphosphines containing chiral phosphorus centres. Other approaches to P-chiral ferrocenyl ligands and biaryl ligands are also described and modifications for further development are implicated. An X-ray crystallographic study of six aryl-oxazaphospholidines is also presented and demonstrates the influence of the substituents at phosphorus in determining the conformation of the 1,3,2-oxazaphospholidine ring. A comparison with solution <sup>1</sup>H n.m.r. data showed, in some cases, good correlation between the P-O-C-H dihedral angle and the corresponding solid state torsion angle.
31
Palin, Michael G. "Synthesis and structure of diene-iron and arene-chromium complexes containing phosphine ligands." Thesis, Keele University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357157.
Testo completo
32
Cieślikiewicz-Bouet, Monika. "Synthesis, structural investigations and evaluation of pyrazine sensitizers for lanthanides emitting in near-infrared and novel phosphine derivatives." Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2088.
Testo completoAbstract (sommario):
En raison de l’omniprésence des hétérocycles azotés et de leurs propriétés biologiques, une attention particulière est accordée au développement de méthodologie pour leur synthèse et leur fonctionnalisation. L’étude de la fonctionnalisation d’énamides constitue une thématique importante car ces motifs s’avèrent être des outils synthétiques polyvalents permettant d’accéder à des dérivés hétérocycliques complexes. Les réactions de couplage Pd-catalysées constituent une méthode de choix rapide et efficace pour la synthèse d'énamides, notamment à partir de phosphates d'énols issus de lactames, d’imides ou d’amides. Le premier chapitre de ce travail porte sur le couplage organopalladié C-P de phosphines boranes secondaires chirales ou achirales avec des phosphates d’énols. Ce couplage C-P original, réalisé dans des conditions douces, conduit aux énamido-phosphines boranes correspondantes et offre de nombreuses possibilités pour la constitution d’une librairie de phosphines originales. Parallèlement à ce travail, l’addition nucléophile d’anions phosphures sur divers ène-carbamates acycliques conduit à des acides alpha-aminés béta-phosphorés originaux, porteurs d’un carbone quaternaire en alpha de l’azote. Le deuxième chapitre de la thèse porte sur la préparation et la caractérisation de chromophores organiques originaux basés sur un noyau pyrazinique et qui sont susceptibles de présenter des propriétés de fluorescence. Ces composés sont conçus pour former des nouveaux systèmes sensibilisateurs de cations de lanthanides, et être utilisés comme sensibilisateurs organiques pour l'imagerie moléculaire dans le proche infrarouge<br>On account of the ubiquity of nitrogen heterocycles and their biological properties, the great attention is paid to developing methodologies of their synthesis and functionalization. For this purpose, the study of functionalization of enamides constitutes an important topic due to the utility of these motifs in the construction of complex heterocyclic derivatives. Palladium-catalyzed reactions of cross- coupling are rapid and efficient methods of choice for synthesis of enamides particularly starting from enol phosphates derived from lactams, imides or amides. The first chapter of the thesis evokes the original C-P coupling reaction of chiral and achiral secondary phosphine boranes with different enol phosphates in mild reaction conditions, leading to corresponding enamido-phosphine boranes. This methodology permits the construction of libraries of novels phosphines. Also, the reaction of nucleophilic addition of phosphide anions onto various enecarbamates acyclic was elaborated, giving an access to original beta-phosphino alpha-amino acids, bearing the quaternary carbon on alpha position to nitrogen. The second chapter is devoted to the preparation and characterization of organic chromophores based on the pyrazinic core, which are likely to exhibit the fluorescence properties. These compounds were designed to form new sensitizing systems for lanthanide cations and could be used as organic sensitizers for molecular imaging in near infrared
33
Ballard, Beau Jurisson Silvia S. "Synthesis and evaluation of ¹⁰⁵Rhodium (III) complexes of phosphine chelate systems." Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/6693.
Testo completoAbstract (sommario):
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 25, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Silvia Jurisson. Vita. Includes bibliographical references.
34
Hirai, Satoko. "The synthesis and applications of a biaryl-based asymmetric phosphine ligand." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32490.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.<br>Includes bibliographical references.<br>The asymmetric biaryl backbone of a dialkylbiphenyl phosphine ligand was developed, synthesized, and resolved. The application of the chiral phosphine ligand to the asymmetric Suzuki-Miyaura cross-coupling reaction was also investigated. This phosphine ligand has yielded promising results in the asymmetric Suzuki-coupling of hindered boronic acids with the electron-rich aryl bromide, 1-bromo-2- methoxynaphthalene, to synthesize biaryls in modest enantioselectivity.<br>by Satoko Hirai.<br>S.M.
35
Silva, Fortes Antonio Belmiro Gil da. "Synthesis and applications of chiral phosphine ligands to catalytic asymmetric hydrogenation." Thesis, University of Liverpool, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359177.
Testo completo
36
Al-Saadi, Sultan. "Synthesis and coordination chemistry of complexes of chelating phosphine-carbene ligands." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/90079/.
Testo completoAbstract (sommario):
Results presented and discussed in this thesis are collected into 4 chapters. Chapter 1 is an introduction to the synthesis and properties of phosphine and N-heterocyclic carbine compounds and complexes. Related complexes of N-heterocyclic carbine-phosphine ligands are also reviewed in this chapter. The synthesis and characterisation of a new phosphine-functionalized N-heterocyclic carbine ligand precursor, 2.5, is described in chapter 2. A synthetic route has been successfully established for this ligand which is designed with N-methyl group on one side of the imidazole core and a pendant PR2 moiety on the other side, (where R = Pri). The ring between the phosphorus group and the imidazolium ring is bound directly to give the rigidity to the whole chelating ligand structure. The corresponding phosphine-NHC ligand was generated in situ and reacted with suitable metal precursors. In addition, the reactivity of the ligand under various conditions was shown to cause cleavage of THF with concomitant formation of an alcohol group attached to the carbene's carbon atom, 2.7. Chapter 3 describes reactions with metal precursors in the presence of a base (via free carbine) or via silver transfer agents and afforded a number of new metal complexes of the phosphine-NHC ligand. These included complexes of groups 11, 10, 9 and 7: Au (3.1), Ag (3.2), Cu (3.3), Ni (3.4), Pd (3.5), Pt (3.6), Mn (3.7) and Ir (3.8). The synthesis of Ag(I) complex was achieved by the reaction of the ligand, phosphine-imidazolium salt (2.5) with Ag2O. The synthesized phosphine N-heterocyclic carbine complexes were characterised by analytical and spectroscopic methods and in some cases by X-ray crystallography. Chapter 4 lists other attempted complexations which did not succeed to yield desired products.
37
Kawai, Masahiro. "Synthesis and Application of Transition Metal Complexes Bearing Overcrowded Phosphine Ligands." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/124436.
Testo completo
38
Smith, Martin Barry. "The synthesis, characterisation and catalytic properties of nickel, palladium and platinum complexes with tris(hydroxymethyl)phosphine and tris(cyanoethyl)phosphine." Thesis, University of Bristol, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303781.
Testo completo
39
Pandrapragada, Ravi Kumar. "Synthesis and characterization of novel phosphinimine ligand systems for potential applications in radiopharmaceuticals." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5100.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Missouri-Columbia, 2007.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Nov. 1, 2007). Vita. Includes bibliographical references.
40
Thai, Susan D. "Progress towards the synthesis of novel ansa-zirconocenes containing alkene or phosphine linkers." Click here for download, 2008. http://proquest.umi.com/pqdweb?did=1625774021&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.
Testo completo
41
Ray, Matthew James. "Synthesis and reactivity of peri-substituted phosphines and phosphonium cations." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3866.
Testo completoAbstract (sommario):
The clean reaction of 5-lithio-6-diisopropylphosphinoacenaphthene (1') with dichlorophosphines, RPCl₂ (R = Ph, Fc, NMe₂, iPr), led to the formation of peri-substituted phosphino-phosphonium chloride salts 2-5. The synthetic utility of these salts was demonstrated in a range of reactions. Mixed tertiary/secondary bis(phosphines) (6 and 7) were prepared by the LiAlH₄ reduction of phenyl or ferrocenyl phosphino-phosphoniums (2 and 3), and the bis(borane) adduct of 6 was prepared by reduction of 2 with BH₃•SMe₂. Reaction of 2 and 3 with a large excess of MeOTf at elevated temperature gave 1,2-diphosphoniums (11 and 12), which were subjected to reduction and co-ordination to a molybdenum(0) centre. An investigation into the co-ordination chemistry of 2 revealed three distinct modes of reactivity. In the reaction with [(nor)Mo(CO)₄] the Mo(0) complex [(2)Mo(CO)₄Cl] (18) was isolated, in which monodentate co-ordination was observed. [PtCl₂(cod)] reacts with the chloride and triflate salts of 2 to form [(2Cl)PtCl₂] (19) and [((2Cl)PtCl)₂][TfO]₂ (21) respectively, both of which show co-ordination of 2 as a bidentate phosphine/chlorophosphine ligand. A palladium(II) dimer (22) in which 2 forms a chelating phosphine/phosphide ligand was isolated from the oxidative addition of 2 to a palladium(0) complex. The geminally bis(peri-substituted) tridentate phosphine (27) was prepared by reaction of 1' with half an equivalent of iPrPCl₂. 27 has a rather strained geometry, and displays restricted dynamics on an NMR timescale, which leads to anisochronicity of all three phosphorus nuclei at low temperatures. Strained bis and tris(sulfides) 28 and 29 and the bis(selenide) 30 have been isolated from the reaction of 27 with sulfur and selenium, respectively. A series of co-ordination complexes, [(27)Cu(MeCN)][BF₄] (32), [(27)PtCl][Cl] (33), [(27)FeCl₂] (34) and fac-[(27)Mo(CO)₃] (35), with tetrahedral, square planar, trigonal bipyramidal and octahedral geometries, respectively, were synthesised. In all of these complexes the tris(phosphine) backbone is distorted, but to a significantly smaller extent that in the chalcogenides 28-30.
42
Cheemala, Narasimha Murthy. "Synthesis of New Chiral Phosphine Ligands and Their Applications in Asymmetric Catalysis." Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-73832.
Testo completo
43
Klüh, Katharina. "Primary phosphine halfsandwich complexes of iron and ruthenium synthesis and hydrophosphination reactions /." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981723179.
Testo completo
44
Chapman, Charlotte Grace. "Design, synthesis and applications of hydroxylmethyl-aryl phosphine oxides in phosphorus catalysis." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/30361/.
Testo completoAbstract (sommario):
Organophosphorus-mediated reactions are important tools in organic chemistry and are used in the synthesis of highly desirable drug targets, such as morphine.1 A major drawback of traditional phosphorus-mediated reactions is the formation of stoichiometric amounts of phosphine oxide by-products; this renders the product purification difficult and reduces the atom efficiency of these transformations. For these reasons, catalytic variants become desirable; there being two potential strategies to achieve the catalysis; i) redox-driven and ii) redox-neutral.2-4 The redox-driven catalytic cycle requires a reductant for the turnover whilst the redox-neutral system uses a sacrificial reagent to directly turn over the phosphine oxide to the active phosphorus (V) reagent. This thesis will report upon a new class of Hydroxylmethyl-Aryl phosphine 1 and phosphine oxide 3 catalyst for use in a redox-driven catalytic reaction; the Staudinger reduction Scheme 1, and routes to a potential redox-neutral catalytic Mitsunobu reaction Scheme 2.
45
Haji-Cheteh, Chehasnah. "Synthesis of phosphine-alkene ligands and 3-hydroxy piperidines using organolithium chemistry." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/13889/.
Testo completoAbstract (sommario):
This thesis describes synthetic routes to P-stereogenic phosphine-alkene ligands and 3-hydroxy piperidines containing heteroaromatics via lithiation-trapping of phosphine boranes or N-Boc pyrrolidine. Both topics are introduced in chapter 1.Chapter 2 presents a route to a new type of P-stereogenic phosphine-alkene ligand B prepared by racemic lithiation of t-butyldimethylphosphine borane or dimethylphenylphosphine borane using s-BuLi. Different allylic halides were used to trap the lithiated intermediate to give chiral alkene-phosphine boranes A. In chapter 3, 3-hydroxy piperidines were synthesised from the ring expansion of hydroxy pyrrolidines. Two novel, short and simple synthetic routes were developed (as shown below). Lithiation-trapping reaction of N-Boc pyrrolidine C using pyridine carboxaldehydes gave N-Boc pyrrolidine alcohols syn-D and anti-D. On the other hand, an alternative approach to obtain 3-hydroxy piperidines anti-H starting from N-trityl prolinal E derived from (S)-proline was investigated. Addition of lithiated heteroaromatics, generated from a Br/Li exchange reaction, to N-trityl prolinal E diastereoselectively gave N-trityl alcohols anti-F. The Boc or trityl deprotection and reductive amination then gave N-benzyl pyrrolidines syn-G and anti-G. Finally, the ring expansion via an aziridinium ion of alcohols syn-G and anti-G gave 3-hydroxy piperidines syn-H and anti-H. The stereochemistry of 3-hydroxy piperidines syn-H and anti-H was proven using J-values in the 1H NMR spectra.
46
Sheu, Biing-Jahn. "The synthesis and characterization by use of spectroscopic and x- ray methods of bromo, phosphine, and nitro derivatives of 13-phenyl- 1,4,7,10-tetraoxa-13-azacyclopentadecane." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834528.
Testo completoAbstract (sommario):
The phenyl ring in the crown ether, 13-phenyl-1,4,7,10-tetraoxa-13-azacyclopentadecane (I), was used a site for functionalizing the compound. Electrophilic bromination of the ring with tribromide ion gave a 95% yield of the product substituted in the para position. This product underwent lithium-bromine exchange when reacted with n-butyllithium. The resulting anion was used to prepare PhZPX and PhPX2 derivatives, X p-C6H4NCH2(CH2OCH2)4&12 The oxide of PhZPX was completely characterized by an x-ray diffraction study which showed, in general, that the phosphorus was tetrahedral, the nitrogen planar, and the crown ether ring organized with the oxygen atoms endodentate. Several attemps were made to nitrate or nitrosate the phenyl ring in the parent crown ether. Spectroscopic evidence obtained from the products indicate that the reaction led to mixtures of mono and disubstituted products.<br>Department of Chemistry
47
Yeung, Ka Yim. "Studies on asymmetric reactions and catalysis using axially chiral 2-substituted N, N-dialkyl-1-naphthamides and p-chiral secondary phosphine oxides /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202003%20YEUNG.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.<br>Includes bibliographical references (leaves 196-207). Also available in electronic version. Access restricted to campus users.
48
Eichenseher, Sandra. "Rhenium-containing phosphines and phosphine oxides new design strategies for highly active and, or enantioselective organometallic catalysts for organic synthesis /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975727532.
Testo completo
49
Wood, Paul A. "Synthesis and characterization of novel bismaleimides derived from arylene phosphine oxides and ether-ketones." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/39889.
Testo completo
50
Wood, Paul A. III. "Synthesis and characterization of novel bismaleimides derived from arylene phosphine oxides and ether-ketones." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/39889.
Testo completo